Astacus leptodactylus: Gherardi, F. & Souty-Grosset, C.

Author(s):  
1979 ◽  
Vol 78 (1) ◽  
pp. 281-293
Author(s):  
MIKKO HARRI ◽  
ERNST FLOREY

1. Crayfish, Astacus leptodactylus, were acclimated to 12 °C and to 25 °C. Nerve muscle preparations (closer muscle of walking legs) were subjected to temperatures ranging from 6 to 32 °C. 2. The resting membrane potential of muscle fibres was found to increase with temperature in a linear manner, but with a change in slope at around 170 in cold-acclimated preparations, and around 24 °C in warm-acclimated ones. 3. Temperature acclimation shifted the temperature range of maximal amplitudes of fast and slow e.j.p.s toward the acclimation temperature. Optimal facilitation of slow e.j.p.s also occurred near the respective acclimation temperature. 4. E.j.p. decay time is nearly independent of temperature in the upper temperature range but increases steeply when the temperature falls below a critical range around 17 °C in preparations from cold-acclimated animals, and around 22 °C after acclimation to 25 °C. 5. Peak depolarizations reached by summating facilitated e.j.p.s are conspicuously independent of temperature over a wide range (slow and fast e.j.p.s of cold-acclimated preparations, fast e.j.p.s of warm-acclimated ones) which extends to higher temperatures after warm acclimation in the case of fast e.j.p.s. In warm-acclimated preparations the peak depolarization of slow e.j.p.s first falls then rises and falls again as the temperature increases from 8 to 32 °C. 6. Tension development elicited by stimulation of the slow axon at a given frequency reaches maximal values at the lower end of the temperature range in cold-acclimated preparations. The maximum is shifted towards 20 °C after warm acclimation. Fast contractions decline with temperature; possible acclimation effects are masked by the great lability of fast contractions in warm-acclimated preparations. 7. It is suggested that changes in the composition of membrane lipids may be responsible for the effects of acclimation on the electrical parameters and their characteristic temperature dependence.


2001 ◽  
Vol 204 (5) ◽  
pp. 933-940 ◽  
Author(s):  
J. Forgue ◽  
A. Legeay ◽  
J.C. Massabuau

Numerous water-breathers exhibit a gas-exchange regulation strategy that maintains O(2) partial pressure, P(O2), in the arterial blood within the range 1–3 kPa at rest during the daytime. In a night-active crustacean, we examined whether this could limit the rate of O(2)consumption (M(O2)) of locomotor muscles and/or the whole body as part of a coordinated response to energy conservation. In the crayfish Astacus leptodactylus, we compared the in vitro relationship between the M(O2) of locomotor muscles as a function of the extracellular P(O2) and P(CO2) and in vivo circadian changes in blood gas tensions at various values of water P(O2). In vitro, the M(O2) of locomotor muscle, either at rest or when stimulated with CCCP, was O(2)-dependent up to an extracellular P(O2) of 8–10 kPa. In vivo, the existence of a night-time increase in arterial P(O2) of up to 4 kPa at water P(O2) values of 20 and 40 kPa was demonstrated, but an experimental increase in arterial P(O2) during the day did not lead to any rise in whole-body M(O2). This suggested that the low blood P(O2) in normoxia has no global limiting effect on daytime whole-body M(O2). The participation of blood O(2) status in shaping the circadian behaviour of crayfish is discussed.


Author(s):  
Serpil Mişe Yonar ◽  
Muzaffer Harlıoğlu

In this study, the effects of selenium added to the diets of Astacus leptodactylus at different ratios on paraoxonase (PON) and arylesterase enzyme activities (ARE) in the hepatopancreas and gonad tissues were investigated. In this study, control (K), trial 1 (D1), trial 2 (D2) and trial 3 (D3) were prepared at the selenium levels of 0,3, 0,6, 0,9 and 1,2 mg/kg, respectively. The crude protein and total energy levels of experimental diets were equalized. 12 ponds in 2 × 2 × 1 m dimensions were used. 75 female and 25 male crayfish were stocked in each pond (totally 1200 crayfish). This study was carried out in triplicate. The crayfish were fed twice a day during 9 months. PON and ARE enzyme activities were investigated in the tissue samples taken monthly from the crayfish. During the trial, significant differences were observed in the PON and ARE enzyme activities in the hepatopancreas and gonad tissues. The PON and ARE enzyme activities increased statistically significant in the crayfish tissues during the breeding season and incubation period. This increase was found to be statistically different in the D1, D2 and D3 groups compared to the control group. In conclusion, selenium had positive effects on PON and ARE enzyme activities of A.leptodactylus during its mating, pleopodal egg laying and pleopodal egg carrying periods.


Crustaceana ◽  
2017 ◽  
Vol 90 (11-12) ◽  
pp. 1289-1302 ◽  
Author(s):  
Yavuz Mazlum ◽  
Ozlem Guner Gurlek ◽  
Sinem Sirin

Substrate is a key factor for successful crayfish culture, and it can be used to increase the survival rate. The effects of substrate on the survival and growth ofAstacus leptodactylusEschscholtz, 1823 were evaluated in flow-through compartments, divided into three sections and with two different substrates, over a period of 90 days. The three treatments used in the study were: artificial ropes, small stones, and a control group that received no substrate. The survival rate was highest in the small-stones treatment group (77.3%) and was lowest in the without-substrate treatment group (41.3%), while the artificial-ropes group showed an intermediate value (65.3%). Total yield was lower in the control group, 22.46% (25.0 g) as compared to the small-stones treatment group, with 42.3% (51.3 g) and the artificial-ropes treatment with 35.51% (55.8 g). In addition, cheliped injuries were found in higher proportion in the group without cover, and the artificial ropes yielded better results compared to the small-stones and no-substrate group in regard of the growth-increase rate.


Crustaceana ◽  
1993 ◽  
Vol 65 (2) ◽  
pp. 176-191 ◽  
Author(s):  
Krzysztof Jaźdźewski ◽  
Alicja Konopacka

AbstractThe paper presents a survey of Polish malacostracan fauna. In two tables the distribution of freshwater and Baltic species is presented according to the regionalization of the country used in "Catalogus Faunae Poloniae". Figures present some interesting distributions of freshwater malacostracan taxa. Own studies as well as the review of ample literature aimed at the preparation of the successive issues of "Catalogus Faunae Poloniae" allowed to present this survey of 121 malacostracan taxa, viz., Bathynellacea - 1 species, Mysidacea - 9, Amphipoda - 50, Isopoda - 47, Tanaidacea - 1, Cumacea - 1, Euphausiacea - 1, Decapoda - 11. In inland waters 31 species and subspecies do occur (Batynellacea - 1, Mysidacea - 1, Amphipoda - 22, Isopoda - 2, Decapoda - 5). In brackish waters of the Baltic Sea and its lagoons- 54 species (Mysidacea - 8, Amphipoda - 24, Isopoda - 12, Tanaidacea - 1, Cumacea - 1, Euphausiacea - 1, Decapoda - 8). Bi-environmental species are Asellus aquaticus and Eriocheir sinensis. The land malacostracan fauna of Poland includes 4 amphipod and 34 isopod (oniscoid) taxa. The Polish malacostracan fauna is composed mainly of species that have invaded this region of Europe in the postglacial period, but the oldest, preglacial elements are subterranean amphipods (niphargids, Crangonyx) and Bathynella natans, occurring only in southern Poland. The earliest postglacial invaders of the Baltic and/or the northern lakes were glacial relict species like the Mysis relicta group, Pallasiola quadrispinosa, Monoporeia affinis and Saduria entomon. The Southern Baltic malacostracan fauna is dominated by Boreal and Arctic/(Subarctic)-boreal elements but one third of this fauna is Mediterranean-boreal or Lusitanian-boreal in origin. Inland waters were probably settled next by Gammarus lacustris, G. pulex, Synurella ambulans, Asellus aquaticus and Astacus astacus, then by later incomers, like Gammarus balcanicus. Canal constructions in the XVIIIth century helped the immigration of Ponto-Caspian elements: Corophium curvispinum and Echinogammarus ischnus. Intentionally introduced to Polish waters are Astacus leptodactylus, Orconectes limosus and Pacifastacus leniusculus; unintentionally brought along were Eriocheir sinensis and Rhithropanopeus harrisii tridentatus, as well as Talitroides alluaudi and Trichorhina tomentosa to some greenhouses.


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